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TRANSCRIPT
Z . C O L IUsing frying oil to produce trans-zeatin in
an engineered strain of E. coli
Colorado State University iGEM
Giant Jamboree 2015
Background
3 billion gallons produced per year in US[1]
Breakdown used frying oil to produce zeatin
1. US EPA. “Learn About Biodiesel”. Web. 8 Jan 2014. Retrieved 20 Aug 2014.
2. Photograph courtesy of Dan Dickinson. Used with permission under creative commons with attribution.
Our Project
ExtracellularBreakdown
TransportMEP
PathwayZeatin
IntracellularBreakdown
Why frying oil?
High energy
CheapFatty acids { } Glycerol
Limiting Steps in Breakdown
Breakdown of Frying Oil Components
Breakdown of Fatty Acids
Transport of Fatty Acids
Breakdown of DAGs
Lipase from Bacillus stearothermophilus
Turns DAGs into FAs and Glycerol
http://www.emhmagazine.com/uploaded/images/123035292.jpg
Transport of LCFAs into Cell
Natural Transporter: long-chain fatty acid outer membrane porin
Encoded for by fadL
Increased Breakdown of FAs
Beta-oxidation pathway
fadD encodes limiting enzyme
Fatty acyl-CoA synthetase
faddfadD Experiment
Growth Experiment with Used Frying Oil
Growth Experiment with Used Frying Oil
Growth Experiment with Used Frying Oil
Initial 50% Solution 50% Solution after 12 hours of Growth
Future Improvements
Quantitative vs. Qualitative Data
Cell Growth Measurement
Optimize Feed and Growth Conditions
Metabolic Engineering
Trans-zeatin
Very expensive
Currently only used in research
Many other applications
https://en.wikipedia.org/wiki/Zeatin
Plant Growth Experiment
Biological Activity of the tzs Gene of Nopaline Agrobacterium tumefaciens GV3101 in Plant Regeneration and Genetic Transformation (Zhao-Fen Han et al., 2013)
MEP Pathway
D-Glyceraldehyde 3-phosphate Pyruvate
MEP
HMBDP
http://www.pet.hw.ac.uk/research/fast1/research/res_images/chem_inhibitors/hmdp.gif
Biosynthesis PathwayZeatin Biosynthesis
Trans-zeatin Synthase
LOGzeatin
https://en.wikipedia.org/wiki/Zeatin
zeatin riboside 5’-phosphate N6-dimethylallyladeninehydroxylation
HMBDPhttp://www.pet.hw.ac.uk/research/fast1/research/res_images/chem_inhibitors/hmdp.gif
Characterization
Zeatin Construct Growth Experiment
Extraction methods Solid Phase Extraction Methods
1. Column Wash
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2. Bind Supernatant 3. Wash
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4. Elute
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Zeatin HPLC Results
Design Considerations
http://instalacionesgrau.com/en/products/bioreactores/
https://pbs.twimg.com/media/CE4Ad2JWAAA6Rp4.jpg
KillerRed
Killer Red Literature
Bulina, M., et. al. "A genetically encoded photosensitizer.” Nature Biotechnology, 95-99. 2005. October 2014.
Kill Switch
• Functional improvement• Removed trp promoter
• Characterization improvement• Collected data on efficacy
KillerRed Improvement
Control KillerRed
Kill Switch Constructs
Improved characterization of KillerRed biobrick
Suspected mutation
Working in a jury-rigged darkroom with KillerRed
interlabInterlab Study
Research
Industry
Public
Spoke with experts and compiled articles on:
Laws and regulation of GMOs
Commercialization and industry
Intellectual property
Bridging the Gap
EntrepreneuershipEntrepreneurship
• Construction and submission of multiple BioBrick Parts (Bba_KI702000-Bba_K1702005)
• Experimental validation of fatty acid breakdown (BBa_K1702001, Bba_K1702002)
• Addressed questions beyond the bench about IP, commercialization, and bridging the gap between academia, industry, and the public
• Used beyond the bench IP research to file provisional patent
• Improved function and characterization of previously existing BioBrick Part, KillerRed (Bba_K1495000)
• Functional prototype of E. coli growing on frying oil
Key Achievements
Key challenges
• Reworking breakdown construct ideas after fadDexperiment
• Inconclusive results about trans-zeatin production
• Proper handling and experimental design for testing KillerRed
Key Challenges
Thank You
Dr. Christie Peebles, Dr. Tom Santangelo, and Dr. Ashok Prasad
Fatty acid growth experimentsLac Promoter
"Lac operon-2010-21-01" by Lac_operon.png: G3proderivative work: Tereseik (talk) - Lac_operon.png. Licensed under CC BY 2.0 via Commons - https://commons.wikimedia.org/wiki/File:Lac_operon-2010-21-01.png#/media/File:Lac_operon-2010-21-01.png
Growth Experiment with 100% Used Frying Oil
Before Inoculation
After 4 hours of growth
Fatty acid growth experimentsFatty Acid Growth Experiment
-0.005
0
0.005
0.01
0.015
0.02
0.025
0.03
0 2 4 6 8 10 12 14 16 18 20
OD
60
0
Time [hr]
E. coli Growth on 0.04% Used Frying oil
fadD + fadL
fadD
fadL
lac Promoter
Why Zeatin?
Benefits:• Increase lateral bud growth• Increases immunity against pathogenic attack on plants[1]
• Anti-aging properties• Green (natural) product• Synthetic production is complex and low yield
Competitors:Benzyl adenine• Synthetic• Not as well researched• Zeatin is 10x more effective[2]
1. Grubkinsky, Dominik et al. ‘Cis- and trans- zeatin differentially modulate plant immunity’. Plant Signal Behav. 2013 8(7); e247982. Bajaj, Y.P.S. Plant Protoplasts and Genetic Engineering IV 2012. Springer Science and Business Media.
Zeatin Biosynthesis
MEP Pathway fullMEP Full Pathway
Tz bioreactor with dataTrans-zeatin Bioreactor Data
Killer red dataKiller Red Data